DESCRIPTION ( Adapted from applicants abstract): This proposal is directed at understanding the interaction of Salmonella with host mononuclear phagocytes. Two Aims are proposed to understand this interaction. The first is to confirm the role of OmpC in bacterial adhesion to macrophages. The gene encoding OmpC will be inactivated by transposon mutagenesis. The ompC gene will be cloned into E. coli, and the OmpC protein will be synthesized and analyzed for biological activity. The second aim is to identify macrophage receptors involved in binding S. typhimurium. Separated macrophage proteins will be probed with OmpC. The isolated proteins will be sequenced to obtain information about the receptors on macrophages involved in the recognition of S. typhimurium.